Power and energy production of PV modules statistical considerations of 10 years activity

The Nominal Power of PV module (Pn) measured at STC, the only standard parameter stated by the manufacturers, only partially describes module performance and does not give any information about energy production; in fact two modules with equal power may have dissimilar energy production. At the LEEE-TISO Test Centre, the most commonly sold modules on the market undergo a series of tests in order to examine their quality and reliability in terms of energy production (Wh/W) and power degradation over time. The testing procedures we developed over the years were slightly modified in order to evaluate the initial degradation of silicon crystalline module. In 10 years of activity around 80 different types of modules have been tested: a summary of this activity is also presented in this paper.